86 



Observations on the Glazing of Hot-houses, 



but in such cases strict attention should be paid, to make 

 the panes fit as exactly as possible on each other. 



The Circular Glazing, so well described by Mr. Gowen, 

 in the Paper above alluded to, has none of the faults of the 

 horizontal glazing ; the lap can be almost entirely puttied 

 up, so as to confine the heat within the house, or prevent a 

 strong wind blowing the cold air into it ; and the small aper- 

 ture left in the centre carries off all the condensed steam over 

 the outside of the glass, down the centre of the pane, in the 

 same course as the external water. Mr. Taylor, however, 

 by his account of the comparison between his method and 

 the circular glazing, did not experience that exemption from 

 loss by the effect of frost, which is attributed to the latter. 

 He states, that in the winter preceding the date of his com- 

 munication, one-fifth of his circular-edged panes were broken, 

 for the most part down the middle of each. The experi- 

 ment in the garden of the Society has yielded a different 

 result. In the late winter, which perhaps has been the most 

 injurious to glazed houses of any within recollection, not 

 only on account of the intenseness of the cold, but from the 

 alternate, and repeated occurrence of freezing and thawing, 

 (the latter consequently producing wet, which, by getting 

 between the laps, and being there frozen, might have caused 

 the glass to crack), not a single pane of the three ranges of 

 circular glazed lights has been injured. Some cause for the 

 difference between the two experiments cited, must have ex- 

 isted ; the shape of the glass, and the mode of laying in the 

 putty, were exactly similar; but the laps in Mr. Taylor's 

 lights were half an inch broad, whilst those in the garden of 

 the Society did not exceed one-eighth of an inch. The pro- 



